Breast Cancer Stages and Surgery

Surgery is the mainstay of therapy for breast cancer. The choice of which type of surgery is based on a number of factors, including the size and location of the tumor, the type of tumor and the person's overall health and personal wishes. Breast-sparing surgery is often possible.

The cancer is staged, using the information from surgery and from other tests. Staging is a classification that reflects the extent and spread of a tumor and has an impact on treatment decisions and also the prognosis for recovery.

Staging in breast cancer is based on the size of the tumor, which parts of the breast are involved, how many and which lymph nodes are affected, and whether the cancer has metastasized to another part of the body.

Cancers may be referred to as invasive if they have spread to other tissues. Those that do not spread to other tissues are called noninvasive. Carcinoma in situ is a noninvasive cancer.

Breast cancer is staged from 0 to IV. You might see a TNM staging system which is based on the tumor size, lymph node involvement, and whether metastasis has occurred. This TNM system is used to determine the final staging from 0 to IV.

Stage 0 is noninvasive breast cancer, that is, carcinoma in situ with no affected lymph nodes or metastasis. This is the most favorable stage of breast cancer.

Stage I is breast cancer that is less than 2 cm (3/4 in) in diameter and has not spread from the breast.

Stage II is breast cancer that is fairly small in size but has spread to lymph nodes in the armpit or cancer that is somewhat larger but has not spread to the lymph nodes.

Stage III is breast cancer of a larger size, greater than 5 cm (2 in), with greater lymph node involvement, or of the inflammatory type.

Stage IV is metastatic breast cancer: a tumor of any size or type that has metastasized to another part of the body. This is the least favorable stage.